INRA, UR1037, LPGP, Fish Physiology and Genomics Rennes, France.
Evol Appl. 2013 Apr;6(3):486-96. doi: 10.1111/eva.12032. Epub 2012 Dec 3.
All salmonid species investigated to date have been characterized with a male heterogametic sex-determination system. However, as these species do not share any Y-chromosome conserved synteny, there remains a debate on whether they share a common master sex-determining gene. In this study, we investigated the extent of conservation and evolution of the rainbow trout (Oncorhynchus mykiss) master sex-determining gene, sdY (sexually dimorphic on the Y-chromosome), in 15 different species of salmonids. We found that the sdY sequence is highly conserved in all salmonids and that sdY is a male-specific Y-chromosome gene in the majority of these species. These findings demonstrate that most salmonids share a conserved sex-determining locus and also strongly suggest that sdY may be this conserved master sex-determining gene. However, in two whitefish species (subfamily Coregoninae), sdY was found both in males and females, suggesting that alternative sex-determination systems may have also evolved in this family. Based on the wide conservation of sdY as a male-specific Y-chromosome gene, efficient and easy molecular sexing techniques can now be developed that will be of great interest for studying these economically and environmentally important species.
迄今为止，所有被研究的鲑科鱼类物种都具有雄性异配性别决定系统。然而，由于这些物种之间没有任何共享的 Y 染色体保守同线性，因此仍然存在关于它们是否共享共同的主要性别决定基因的争论。在这项研究中，我们研究了虹鳟（Oncorhynchus mykiss）主要性别决定基因 sdY（性染色体上的性别二态性）在 15 种不同鲑科鱼类中的保守性和进化程度。我们发现，sdY 序列在所有鲑科鱼类中高度保守，并且在这些物种中的大多数中，sdY 是一种雄性特异性的 Y 染色体基因。这些发现表明，大多数鲑科鱼类共享一个保守的性别决定基因座，并且强烈表明 sdY 可能是这个保守的主要性别决定基因。然而，在两种白鲑物种（亚科 Coregoninae）中，sdY 既存在于雄性中，也存在于雌性中，这表明替代性别决定系统也可能在这个家族中进化。基于 sdY 作为雄性特异性 Y 染色体基因的广泛保守性，现在可以开发出高效且易于使用的分子性别鉴定技术，这对于研究这些具有经济和环境重要性的物种将非常有兴趣。
